In a principal aspect, the present invention relates to a molded plastic lid compatible with and designed for attachment to the top of a container or bucket.
The use of one gallon plastic buckets for paint and other liquids has not yet been universally adopted. Nonetheless, there are numerous constructions that have been patented and which are directed to the combination of a molded plastic bucket and lid. Further, the use of a molded plastic lid in combination with a formed metal bucket constitutes an alternative method for packaging liquid materials. Additionally, the concepts of molded plastic containers and lids is not limited to one gallon paint type containers which are generally cylindrical in shape. That is, molded plastic buckets having a five gallon capacity and a compatible lid have been known for some time. Smaller packages utilizing molded plastic lids are known. Further, the configuration of the container or bucket need not necessarily by cylindrical or circular in cross section. Thus, rectangular shaped containers and containers having various other shapes may be provided, and lids compatible therewith may also be provided.
A problem often encountered with such containers is the effective removal of a lid as well as the design of a lid which will provide a good seal of the lid to the top rim of the container. Providing a good seal while also providing a means for removal of the lid is a desirable objective for such containers.
As further background, the designs for molded plastic buckets or containers are disclosed in numerous patents including the following: U.S. Pat. Nos. 4,375,948; 4,574,974; 4,512,494; 4,512,493; 4,452,382; 4,380,305; 4,308,970; 4,210,258; 5,538,154; and 5,437,386. These buckets are containers for food, paint, solvents and chemicals are generally made from molded plastic materials.
Typically, the design of the mouth or upper rim or open end of a plastic bucket or other type of container is designed to be compatible with a lid. The use of a molded plastic lid is a desirable objective. U.S. Pat. No. 5,538,154 entitled “Snap On Flexible Lid” discloses a plastic lid with a peripheral flange that is constructed to enhance the “drop strength” of the lid while maintaining flexibility adequate to permit removal of the lid from a container. Drop strength involves the characteristic of the lid to maintain attachment thereof to a container even when dropped from various heights. U.S. Pat. No. 5,477,386 entitled “Container with Tamper Evident Lid Removal Means” discloses further embodiments of compatible molded plastic lids that are designed to be compatible with the top rim or open end of a bucket.
Despite all of the various constructions, there has remained a need for development of a molded plastic lid having excellent “drop strength”, good sealing capability, and ease of removal and replacement of the lid on the open end of a bucket or other container. It is with these objectives in mind that the present invention was developed.